JPH08218222A - Pile yarn for artificial lawn - Google Patents

Abstract

PURPOSE: To obtain a pile yarn, containing a random copolymer of propylene and an α-olefin other than the propylene as a substrate and having sufficient fibrillation resistance even in an artificial lawn containing sand therein. CONSTITUTION: This pile yarn contains a random copolymer of propylene and an α-olefin (ethylene, 1-butene, 1-pentene, 1-hexene, etc.) other than the propylene as a substrate. The α-olefin other than the propylene is present in an amount of 1-10wt.%, preferably 2-6wt.% in the copolymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pile yarn for artificial grass.

[0002]

2. Description of the Related Art In outdoor ball fields for baseball, soccer, hockey, tennis and other ball sports, multipurpose grounds, parks and the like, synthetic resin yarns such as polypropylene and nylon are used as pile yarns as base fabrics as substitutes for natural grass. The planted artificial grass is widely used. Furthermore, in recent years, because the stadium of sand-containing artificial turf, in which the pile yarns have been coarsely planted and the turf eyes have been filled with a filler such as sand, the drainage and the impact on the athlete's legs have been favorable. It is becoming widespread.

As a material for the pile yarn, polypropylene is widely used because it can impart excellent weather resistance by adding an organic stabilizer and is relatively inexpensive. However, the artificial sand containing sand has a problem in that the tip portion of the pile yarn is likely to be fibrillated due to friction with sand filled when it is stepped on by a shoe or the like.

For the purpose of providing a pile yarn for polypropylene-based artificial turf in which the tip of the pile yarn is hard to fibrillate,
For example, in JP-A-2-112405, a propylene-ethylene block copolymer composed of a chain segment composed of a propylene homopolymer and a chain segment composed of a random copolymer of propylene and ethylene is used as a base material. Slit yarn is disclosed.

Further, for example, in Japanese Unexamined Patent Publication No. 6-184811, 65 to 95% by weight of polypropylene having a melt flow rate of 0.5 to 5 g / 10 min and a density of 0.918.
Artificial turf for yarn comprising a uniaxially stretched product as a base material a resin composition containing a linear polyethylene 35-5 wt% of ~0.940g / cm ³ are disclosed.

However, the slit yarn and the raw yarn obtained by any of the above methods cannot be said to have sufficiently improved resistance to fibrillation and cannot be used as sand-containing artificial grass.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and an object thereof is an artificial grass having sufficient fibrillation resistance even when used as a sand-containing artificial grass. The purpose is to provide pile yarns for use.

[0008]

The pile yarn for artificial grass of the present invention comprises a random copolymer of propylene and an α-olefin other than propylene as a base material.

The random copolymer used in the present invention is
It is a random copolymer of propylene and an α-olefin other than propylene. As the α-olefin other than propylene, ethylene, 1-butene, 1-pentene,
1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and the like can be mentioned.

The above-mentioned random copolymer is a copolymer obtained by simultaneously polymerizing propylene and an α-olefin other than propylene and randomly distributing the α-olefin other than propylene in the propylene chain. The catalyst used in this copolymerization reaction is preferably a Ziegler-Natta catalyst, and a carrier-supported catalyst obtained by supporting a transition metal compound on a carrier such as a transition metal compound such as a titanium-containing compound or a magnesium compound, It is a combination with a promoter of an organometallic compound such as an organoaluminum compound. Further, as a method for polymerizing the random copolymer, any of gas phase polymerization, slurry polymerization and solution polymerization can be used.

When the proportion of α-olefin other than propylene in the constituents of the random copolymer is small, sufficient fibrillation resistance cannot be obtained, and when the proportion is large, the solidification rate becomes slow and stable molding of the film is possible. Since it becomes difficult, 1 to 10% by weight is preferable, and more preferably 2 to 6
% By weight.

When the melt flow rate (value measured according to JIS K7210, hereinafter referred to as "MFR") of the above random copolymer becomes small, extrusion molding becomes difficult, and when it becomes large, it is sufficient as a pile yarn for artificial grass. Since strength cannot be obtained, 0.3 to 9 g / 10 minutes is preferable, and 1 to 7 g / 10 minutes is more preferable.

Another olefin polymer may be added to the random copolymer. Other olefin polymers include low density polyethylene, linear low density polyethylene, high density polyethylene and polypropylene. In this case, the proportion of the random copolymer is preferably 75% by weight or more.

In the pile yarn for artificial grass of the present invention, stabilizers such as light stabilizers and heat stabilizers; additives such as pigments, calcium carbonate, talc and the like, if necessary, within a range not impairing the performance of the pile yarns. May be added by a known method.

In the pile yarn for artificial grass of the present invention, the above-mentioned random copolymer (a composition in which stabilizers and additives are added to the copolymer, if necessary) is molded at a temperature of 200 to 250 ° C.
Then, a film is formed by T-die extrusion molding or inflation extrusion molding, stretched at 110 to 140 ° C. to have a stretch ratio of 4 to 8 times, and splitting treatment is performed, and then 130 to 150.
It is obtained by heat-treating at ℃ and twisting. If the stretching ratio is less than 4 times, the recoverability is poor, and if it exceeds 8 times, the elasticity becomes too high, so 4 to 8 times is preferable.

The above artificial turf pile yarn has a fineness of 2,
000-20,000 denier, yarn width 0.5-50m
m, and a yarn thickness of 30 to 100 μm are preferable. Thread thickness is 3
When it is less than 0 μm, the durability is lowered, and when it exceeds 100 μm, the splitting treatment and the workability of the flocking are deteriorated, so that it is 30 to 10
0 μm is preferable.

The twisting process of the pile yarn for artificial grass is preferably carried out in the twist ratio range of 15 to 55.
The twist ratio (K) is expressed by the following equation. K = (T√D)
/ 100, where D is denier and T is the number of twists (times / m
Each) is shown.

[0018]

The present invention will be described below with reference to examples. (Example 1) MFR = 1.8 g / 10 minutes, 100 parts by weight of an ethylene-propylene random copolymer having an ethylene content of 3.5% by weight, 2 parts by weight of a phthalocyanine-based green pigment, and 0.2 parts by weight of a heat stabilizer. Parts and 0.8 parts by weight of a light stabilizer were added and kneaded, and a sheet was formed by an inflation method at a forming temperature of 240 ° C. 120 sheets obtained
The fiber was stretched with a heating roll at ℃ to a draw ratio of 6 times, split with a splitter, and then heated at 140 ° C. using a heating furnace and a heating roll to obtain a heat shrinkage ratio of 10 at 10 ° C.
The heat treatment was performed so as to be within%. The obtained yarn is twisted so that the twist ratio is 31, and the thickness is 8000 with a thickness of 60 μm.
A pile yarn for denier artificial grass was obtained. This pile yarn was planted with a tufting machine on a polypropylene base fabric having a weight of 100 g / m ³ , and a styrene-butadiene copolymer rubber latex was applied to form a backing material.
It was dried at 0 ° C. to prepare an artificial grass having a denier of 24,000 / cm ² and a fiber length of 20 mm.

(Example 2) An artificial grass was prepared in the same manner as in Example 1 except that an ethylene-propylene random copolymer having an MFR of 6 g / 10 min and an ethylene content of 5.6% by weight was used. Was produced.

Comparative Example 1 An artificial turf was produced in the same manner as in Example 1 except that a propylene homopolymer having an MFR of 5 g / 10 min was used instead of the ethylene-propylene random copolymer.

(Comparative Example 2) Instead of the ethylene-propylene random copolymer, 80% by weight of propylene homopolymer having an MFR of 2.8 g / 10 min and a density of 0.930 g / c.
An artificial turf was produced in the same manner as in Example 1 except that 20% by weight of m ³ linear polyethylene was used.

(Comparative Example 3) A block comprising 75% by weight of a propylene homopolymer of MFR = 2.8 g / 10 minutes and 25% by weight of a random copolymer of ethylene and propylene, in place of the ethylene-propylene random copolymer. An artificial turf was produced in the same manner as in Example 1 except that the copolymer was used.

In the turf of the artificial turf obtained in the above Examples and Comparative Examples, the particle sizes of less than 20 mesh, 20 to 45 mesh and more than 45 mesh are 3% by weight, 92% by weight and 3% by weight, respectively. A sample filled with silica sand to a thickness of about 17 mm was subjected to a crushing / abrasion test for 500 cycles in accordance with the test method of DIN 54322, and then the number of pile yarn splits produced in this test was 10
The fibrillation resistance was evaluated by the value converted per mm and shown in Table 1.

[0024]

[Table 1]

[0025]

The pile yarn for artificial turf of the present invention has the above-mentioned constitution and is excellent in resistance to fibrillation. Therefore, it is an outdoor ball field for ball sports such as baseball, soccer, hockey and tennis, a multipurpose ground and a park. It is preferably used as a sand-containing artificial grass.

Claims (1)

[Claims] 1. A pile yarn for artificial turf, which comprises a random copolymer of propylene and an α-olefin other than propylene as a base material.